An antenna mast may be mounted on a vehicle. The antenna may be used for reception, transmission or both reception and transmission of electromagnetic signals. During vehicle movement or transportation, the maximum antenna height has been limited to a lower transport height to avoid bending, breaking or damage to the antenna from trees, bridges or other obstructions. The limitation in height of the antenna may limit the maximum range of effective communications between the vehicle and a communications device located remotely apart from the vehicle. For example, electromagnetic radiation that is in the microwave frequency range may be limited to propagation in line-of-sight paths or may be severely attenuated by ground clutter where antenna height is insufficient for a requisite level of clearance in accordance with applicable electromagnetic propagation models. For example, the grain bin of a combine may interfere with radio frequency (RF) signal transmission and reception of an antenna at the lower transport height. Accordingly, a need exists for maximizing antenna height of an antenna mounted on a vehicle when the vehicle is within a defined or geofenced area in order to improve the range and reliability of communications and to increase the accuracy of vehicle guidance within that area.